[stevehull]

MMT - just re-read your post on system design. A couple questions and I apologize if you have answered them elsewhere.

Re the open loop radiant system. Does this mean that the radiant loops are heated in the summer? I understand that by drawing off hot water (such as faucets, shower, washers, etc) removes the water from the radiant system and prevents stagnation (legionnaire's dx). But how do you do this without heating up all the loops in the summer?

I have had problems with hooking up a small point of use electric heater to "top off" the heat from a storage tank. The problem was that the small (8 kW) heaters only had a 1/2 inch connection and this restriction caused loss of hot water flow when more than one hot water need was being used. For example, showering and someone turning on the dishwasher. Or, did you put two point of use heaters in parallel?

Thanks again,

Steve